Work

7/3 fractional quantum Hall state in GaAs double quantum wells

Year: 2026

Type: article

Abstract: We observed the fractional quantum Hall effect at a total filling factor of 7 / 3 in the Hall resistance, accompanied by a single minimum in longitudinal magnetoresistance in uncoupled, bilayer electron gases formed in GaAs double quantum well systems. When the density of the top electron gas is varied, the total 7 / 3 ( 1 + 4 / 3 ) state can be tuned such that while the Hall plateau value essentially remains unchanged, the associated longitudinal magnetoresistance develops into a double minimum. When Zeeman energy is introduced by tilting the applied magnetic field, the two minima respond differently; one remains essentially unchanged, while the other deepens, consistent with the differing spin dependences of the integer and fractional gaps. Our results demonstrate that the detailed evolution of the 7 / 3 plateau probes layer-resolved incompressibility, interlayer charge redistribution, and spin-dependent gap behavior in a nontunneling bilayer system.

Source: Physical review. B./Physical review. B

DOI: 10.1103/f33x-cqrr

Authors: Mandun Fu, Ian Farrer, David A. Ritchie, Sanjeev Kumar

Institutions: University College London, University of Sheffield

Language: English

Topic: Quantum and electron transport phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: UK Research and Innovation, Engineering and Physical Sciences Research Council

Awards: G381337513, G8188427576